Conventionally, well conduits were cemented into place in the wellbore. However, the use of cement is sometimes not desirable because it may reduce or interfere with the production of the well. With the introduction of non-cemented wells open hole packers came into use. Initially, the packer designs were mechanical in nature and eventually, swellable packers were introduced.
Swellable packers were initially designed to swell when exposed to oil based fluids. More recently swellable packers which swell in the presence of water based fluids (e.g., brine) are also in use and offer. However, these water swellable packers have drawbacks because the rubber composition is not always acceptable for use in wells and/or the rubber does not sufficiently swell when it contacts saline formation water.
Accordingly, it is desirable to have a water swellable rubber which is more acceptable for use with oil and gas field equipment including, for example, swellable packers.